ABSTRACT Non-AIDS defining cancers (NADCs) are projected to account for 89% of all cancers among people living with HIV (PLWH) by 2030, with the vast majority diagnosed among older PLWH. This shift is concerning because, as compared to people without HIV, PLWH reportedly have higher cancer-specific mortality for several NADCs, and higher overall mortality after diagnosis of the most common NADCs. The explanation for higher mortality among PLWH after a NADC is likely multifactorial and, at present, not fully understood. Given approximately 45% of PLWH are ?50 years, with 84% of those between 50 and 64, it is critical to understand the intersection between HIV, NADCs, and healthy aging in this population. To inform the development of effective NADC prevention and treatment strategies for the aging PLWH population, it is important to be able to disentangle the influence of HIV from the socio-behavioral factors associated HIV acquisition. To do this, a comparison group with a comparable burden of risk factors, socioeconomic status, and access to care is needed. Approximately 40% of PLWH in the US are covered by Medicaid. Medicaid beneficiaries are a diverse population, and include a comparison group for PLWH with similar risk factor burden and access to care. The Medicaid population is an important complement to existing HIV resources, including those that (1) capture cancer incidence but not downstream events, such as the HIV-Cancer Match cohort, (2) include rich cohort data, but have limited specific types of cancer cases to allow for examining race and sex differences, like the NA-ACCORD, and (3) other claims-based cohorts which capture, important, but different segments of the HIV and general population, including SEER-Medicare. We propose to assess claims for more than 5 million Medicaid beneficiaries ?50 years old from 14 states between 2001 and 2017, in the modern era of antiretroviral therapy, to: (1) quantify the age-, race/ethnicity-, and sex- specific incidence of NADCs by cancer type among PLWH (2) evaluate the association between HIV-infection and NADC-specific treatment-related outcomes, (3) evaluate the association between NADC-specific diagnosis and new AIDS-defining illnesses and retention in HIV care, and (4) evaluate whether a diagnosis of both HIV and NADC, by cancer type, is associated with a higher risk of age-related outcomes as compared a diagnosis of HIV or NADC alone. Findings from this study will inform how aging in the presence of HIV affects the risk and consequences of non-AIDS defining cancers, and impacts HIV care and age-related outcomes among older adults. Importantly, we will evaluate our aims among a low-income, diverse population of men and women ?50 years old with a comparison population with comparable risk factors and access to care.